moshang soulmate au where sqh never wrote mbj a soulmate so when he transmigrated with a soulmark that obviously represents mbj he assumes it's a one sided bond and keeps it hidden bc he doesn't want mbj to pity him or assume he has expectations or ulterior motives,
meanwhile mbj has no idea wtf the airplane shaped soulmark he has could possibly mean but he knows he has to keep it a secret bc its a potential weakness
so he deliberately acts like he doesn't have a soulmate and avoids psychics and plants that could help him locate his soulmate bc if he knew who it was he isn't sure he could stay away
for maximum drama at some point mbj gets poisoned by something where the cure is the blood of your soulmate willingly given and whoever did it is sure this will be a successful assassination bc its common knowledge that mbj doesn't have a soulmate
and mbj is also sure he's going to die bc even if he could find the identity of his soulmate in the very limited time he has left (unlikely) his teleporting powers are already unreliable (effect of poison) and he isn't sure he could get them to willingly give him what he needs anyway
the cure won't work if there's blackmail or bribery involved it has to be pure intentioned or whatever and mbj has self esteem issues tbh
so mbj is sulking about this or whatever and sqh is like "my king forgive me" and slices his palm open and holds his hand over mbjs mouth
and mbj gets to go from wtf to WTF ITS WORKING and how long has sqh known (how long has sqh been KEEPING THIS FROM HIM years of such a secret/lie for what!!! is he that undesirable???)
so he is freaking out and pissed bc "why would you let me dishonour myself by treating my soulmate like a mere servant" or whatever and sqh is very "I didn't want to burden you my king so really we can just pretend this never happened"
and mbj is hashtag coping with a lot of feelings and desperately wants a distraction (or for the world to start making sense even though this revelation makes SO MUCH SENSE) and he asks sqh abt what his weird ass mark shape means +shows it to him
and sqh is now ALSO freaking out bc 1. really? a reference to his handle? what did he do to deserve this and 2. MY KING YOU HAVE A SOULMATE?
then u get the whole "YOURE my soulmate" "obviously I'm your soulmate but I'm your soulmate!?!" and an explanation about one sided bonds (very tragic, mbj feels WORSE knowing what sqh was thinking for years)
for extra pizzazz add in an immediate proposal and "you don't have to marry me just because I'm your soulmate + in love with you" speech where mbj learns that sqh also 1. is in love with him and 2. believes it to be a one sided state of affairs
...the doctor would love for this not to be happening bc it would be really awkward to interrupt and check on how the cure is doing but that's kind of her job